Combined bourdon tube and trap



Aug. '22, 1939;

H L. JOYCE 2,170,561

COMBINED BOURDON TUBE AND TRAP Filed May 13, 1952 fwezzfif HgroZdl. kfoyce Patented Aug. 22, 1939.

UNITED STATES PATENT OFFICE COMBINED BOURDON TUBE AND TRAP Harold L. Joyce, Chicago, 11]., assignor to Jas P. 1

Marsh Corporation, Chicago, 111., a corporation of Illinois 12 Claims.

The invention relates to improvements in pressure responsive devices which may be combined with a mechanism for, operating the indicator of a device such as a pressure gauge to actuate said mechanism and indicator.

It is an object of the invention to provide a pressure responsive device with means forming a trap to maintain a quantity of liquid therein and prevent steam or other heated medium from entering said pressure responsive element and affecting said element, yet willallow said pressure responsive element to respond to pressure applied thereto.

It is another object of the invention to provide a pressure responsive element such as a Bourdon tube with means for trapping a quantity of liquid therein so as to accomplish the advantages just referred to.

It is a further object of the invention to provide a device such as a Bourdon tube. with a tubular element which communicates therewith, the tubular element having an end connected with and communicating with a passage provided in a tubular post employed for attaching the device for use.

The invention has these and other objects, all of which will be explained in detail and more readily understood when read in conjunction with the accompanying drawing in which one embodiment of which the invention is susceptible is illustrated, it being evident that changes and modifications may be resorted to without departing from the spirit of the appended claims forming a part hereof.

a structure for accomplishing the invention;

Fig. 2 is a side view of the structure shown in- Fig, 1;, and

Fig. 3 is a section taken on the line 3-3 of The embodiment of the invention illustrated in the drawing contemplates the utilization of a coiled tube-generally designated Ill, one end of which such as H being connected and communicating with the passage l2 of the tubular post l3.

The opposite end H of the coil generally designated i is adapted to expand and contract so as to impart movement to a mechanism such as that generally designated L: for actuating an indicator (not shown) connected with the mechanism.

In the particular structure illustrated, the coil in is'comprised of two arcuate sections respectively designated 96 and IT. The section it is i of an elongated cross section as illustrated in In the drawing, Fig. 1 is a front elevation of Fig. 3 and therefore resembles in cross section the ordinary Bourdon tube now employed in structures of this. character. This tubular section l6 has the end It thereof provided with an element 18 for effecting a connection between this end of the tube l6 and the mechanism generally designated IS. The opposite end I9 of this tube section I6 is inserted into a passage 20 formed in the postl3. The end ll of the tubular section I! is connected for communication with the passage l2 and said tubular section extends from the passage '12 to the passage 20, the end 2| of said tube'section l1 being inserted in the passage 20 and thus a communication is completed between the passage l2 of the post and the tube sections respectively designated l6 and I1.

The portions A and B of the tube sections 16 and I I provide elements of a trap for con fining a quantity of liquid within these portions, the trap being employed to prevent steam from entering the tubular section I6, yet will allow pressure to enter said tubular sections l6 and I1 and act upon the liquid contained in the trap and cause movement of. said liquid relatively to the trap and relatively to the end I4 of the tube section l6 which will cause said end It to be distended and contracted depending upon the pressure existing in the tubular sections 16 and H.

It is evident that as the pressure applied to the liquid in the trap fluctuates, the liquid in the trap will move toward and away from the distensible and contractible end I l of the section l6 causing same to be actuated. Manifestly, as the end I4 is moved by the pressure existing in the coils of the tube, this movement will be imparted to the mechanism l which will actuate the indicator connected with the mechanism. It is also evident that by trapping a quantity of liquid in the expansible and contractible element, steam or other heated medium is prevented from entering this portion thereof and thus this portion is prevented and insured against being eifected by the temperature of the medium under pressure.

In the particular structure illustrated in the drawing, the tubular section It is of an elongated cross section similar to what is known in the art as a Bourdon tube while the tube section I! is of ordinary tube stock-which will materially reduce the cost of producing the device.

From the foregoing description of the invention, it is evident that a device is produced having means responsive to pressure and capable of operating a mechanism for actuating an indicator which device has means whereby the pressure responsive means thereofisprotected against the temperature of the medium under pressure. It is further evident the liquid in said pressure re-. sponsive device is trapped against escape from said device, yet may be moved in opposite directions relatively to the end M of the expansible and contractible section of the tube which will cause movement of this end to take place depending upon the degree of pressure applied to the liquid in said trap. It is further manifest that since the liquid in the trap prevents the introduction of a heated medium under pressure to the tubular section IS, a gauge or other instrument may be produced which uneffected by the temperature of said medium will 'result in the production of an instrument which is of a more accurate character.

Having thus described the invention, what I claim and desire to cover by Letters Patent is:

1. A pressure gauge. comprising a post formed with a longitudinally extending bore for a portion of its length and with a transverse passage therethrough in non-intercepting relation to the longitudinal bore, a Bourdon tube having one end connected to the transverse passage, the free end being movable in response to pressure therein, a tubular element arranged with its opposite ends connected in communication with the longitudinal bore and the transverse passage, respectively, an intermediate portion of said tubular element being disposed above said transverse passage to provide a trap for confining liquid between the ends of said Bourdon tube and said tubular element.

2. A pressure gauge comprising a post formed with a longitudinally extending bore' for a portion of its length and with a passage therethrough adjacent one end of said longitudinal bore, a Bourdon tube having one end connected to the said passage, the free end being movable in response to pressure therein, a tubular element arranged with its opposite ends connected in communication with the longitudinal bore and said passage, respectively, an intermediate portion of said tubular element being disposed above'said transverse passage to provide a trap for confining liquid between the ends of said Bourdon tube and said tubular element. 7

3. A pressure gauge comprising a post formed with a longitudinally extending bore for a. portion of its length and with a transverse passage therethrough beyond the longitudinal bore, a Bourdon tube having one end connected to the transverse passage, the free end being movable in response to pressure therein, a tubular element arranged with its opposite ends connected in communication with the longitudinal bore/and the transverse passage, respectively, an intermediate portion of said tubular element being disposed in spaced relation with respect to said transverse passage and bore to provide a trap for confining liquid between the free end of said Bourdon tube and the pressure receiving end of said tubular'element.

4. A pressure gauge comprising a post having a bore formed therein and a passage extending therethrough, a Bourdon tube having one of its ends positioned in said passage, the opposite end being movable in response to pressure therein, a tubular element having its opposite ends posi-' tioned in said bore and passage, respectively, a portion of said tubular member being disposed in spaced relation with respect to said passage to provide a trap for confining liquid between the movable end of said Bourdon tube and the end of said tubular member positioned in said bore.

pressure therein, a tubular member arranged with its opposite ends in communication with said bore and passage respectively, a portion of said tubular member being disposed in spaced relation with respect to said passage to provide a trap for confining liquid between the ends of said pressure responsive element and said tubular member.

6. A pressure responsive instrument comprising a post formed with a longitudinally extending bore for a portion of its length and with a transverse passage therethrough beyond the 1ongitudinal bore, a Bourdon tube having one end connected to one end of the transverse passage, the free end of the tube being movable in response to pressure therein, and a pressure-transmitting tubular device connected between the longitudinal bore and the other end of the transverse passage and having a loop portion forming with the Bourdon tube a trap for confining a bodyof liquid, the said body of liquid preventing the fluid entering the longitudinal bore from gaining access to the Bourdon tube.

7. A pressure responsive instrument comprising a post formed with a longitudinally extending bore for a portion of its length and with a transverse passage therethrough beyond the longitudi- I nal bore, a pressure-responsive means constituting a Bourdon tube mounted in communication with one end of said transverse passage, and a tubular element in the form of a loop connected between the longitudinal bore and the other end of said transverse passage to transmit pressure from the former to the said Bourdon tube.

8. A pressure responsive device comprising a post formed with a longitudinal bore and a transverse passageway in non-intercepting relation to said bore,a Bourdon tube having one end fixed to saidpost and projecting into one end of said transverse'passageway, the free end of the Bourdon tube being movable in response to pressure therein, and a pressure transmitting device in the form-of a coiled tubular member concentrically arranged outside of said Bourdon tube and wholly supportedupon said post and affording communication between said bore and said fixed end of the Bourdon tube.

9. A pressure responsive device comprising a post formed with a longitudinal bore and a transverse passageway in non-intercepting relation thereto, an expansible and contractible tubular pressure responsive means having one end fixed to said post and communicating with one end of said transverse passageway, and a pressure transmitting tubular device wholly supported upon said post and connected between the said longitudinal bore and the'other end of said transverse passageway in order to transmit pressure from the former into the fixed end of said tubular pressure responsive means, said pressure transmitting tubular device having a loop portion forming with the tubular pressure responsive means a trap to prevent fiuid that enters said longitudinal bore from directly contacting with the said pressure responsive "means.

10. A pressure responsive device comprising a post formed with a longitudinal passage and a transverse passageway in non-intercepting rela tion thereto, a tubular pressure responsive elemunicating with one end of said transverse passageway, and a pipe wholly supported upon said post and having one of its ends in communication with said longitudinal passage and its other end in communication with the said end of said tubular pressure responsive element that projects into said transverse passageway, said pipe having a loop portion forming with said tubular pressure responsive element a trap to retain a body of heat insulating substance therein to protect the pressure responsive element from contact with the fluid thatenters said longitudinal bore.

11. A pressure responsive device comprising a post formed with a longitudinal passage and a transverse passage in non-intercepting relation thereto, a Bourdon tubular element having one end portion anchored to said post within one end of said transverse passagewayQthe free end portion of the Bourdon element being movable in response to pressure therein,and a curved tubular element having one end anchored on said post in communication with said longitudinal passage and its other end anchored within the other end of said transverse passage for establishing communication between said longitudinal passage and the said fixed end portion of the Bourdon element, said curved tubular element constituting a loop to form with said Bourdon element a trap for confining a body of heat insulating substance that prevents the fluid that enters said longitudinal passage from gaining access to said Bourdon element. J

12. A pressure responsive instrument comprising a post formed with a bore and a transverse passageway which are in non-intercepting relation to each other, a tubular pressure responsive means wholly supported upontsaid post and having one end fixed by projecting into said transverse passageway, and a pressure transmitting therein to protect said pressure responsive means from direct contact with the fluid that enters through said bore.

HAROLD L. JOYCE. 

